WSUS gathers huge amounts of “waste” so it’s a good idea to schedule the cleanup to be run once a week.
It’s easy to do following the two great posts:
a) It's rather tragic that you can't schedule Powershell scripts directly but need a .bat wrapper to do the job. After all, this is 2012.b) The link to Peeters is b0rken (and so is the site). I hope it comes back soon, as that link probably was the beef'n'carrot of the whole thing... Not that it's for you to fix, Sami, but it just shows that the web can be volatile at times...
This might help abit atleast: http://www.wsus.info/index.php?showtopic=13977